Articulators for producing dental prostheses have long been known. An articulator is a device, which is arranged to hold plaster models of a patient's upper and lower dental arches. The plaster models mounted on the articulator simulate the physiological closure of the two arches for the purpose of manufacturing bridges, prostheses, etc., in a laboratory.
Referring to FIG. 1, there is shown a conventional articulator 10 having lower and upper ring-shaped bases 12, 14 which pivot about an axis 16 relative to one another. An upper model (not shown), replicating the upper dental arch, is fastened by means of a temporary layer of plaster under the lower face of upper base 14, and a lower model (not shown), replicating the lower dental arch, is fastened by means of a similar layer of plaster to the upper face of bottom base 12. Pivoting bases 12 and 14, with the models mounted thereon, relative to each other simulates the movement of the jaw and the dental structure of the mouth.
A disadvantage of using this conventional articulator is that the only way to remove the models from the articulator is by breaking the temporary layer of plaster. This requires special proficiency and very often results in pieces of plaster remaining on the models, and even in breaking the articulator, itself.
In recent years, plasterless articulators were introduced, aiming to avoid the necessity of affixing the models to the articulators with plaster. The plasterless articulators include two integral plates instead of ring-shaped bases: an upper plate and a lower plate, serving as holders for the dental models. Each of the plates includes a securing mechanism configured to engage and lock the model in position. The articulator may include joints enabling the movement of one or both of the plates in different directions relative to one another. However, replacing the simple conventional articulators with these prior art articulators is a significant expense.
Another disadvantage of these prior art articulators is that the plates are substantially the same size as the dental models. Therefore, there is no access to the bottoms of the models, which can be problematic when trying to dislodge a single tooth or group of teeth from a model on the articulator.
Accordingly, there is a long felt need for an inexpensive articulator that does not require affixing of the dental models with plaster, and it would be very desirable if such an articulator were able to utilize existing, conventional articulators.